Police have confiscated about 300 kilograms of cocaine and other drugs, and discovered seven drug-processing laboratories in both Serbia and Germany, Interior Minister Nebojsa Stefanovic said.

Stefanovic added that the street value of the confiscated drugs was estimated at 20 million euros ($22 million), while police also found weapons and money.

"This is an excellent example of cooperation between the Serbian and German police," Stefanovic said. "It dealt a huge blow to the organized drug cartels."

The suspects included a Belgrade soccer club fan leader, Stefanovic said. He said three suspects remain at large.

In neighboring Montenegro, authorities have arrested nine members of a criminal gang allegedly behind a recent spate in murders in the UNESCO-protected coastal town of Kotor, a top tourist resort.

Seven other suspects are on the run, organized crime prosecutor's office said late Monday. The suspects face drug smuggling, weapons possession and abuse of power charges, the statement said.

Clashes between criminal gangs have threatened the tourist season in Kotor, famous for its old town with narrow stone streets and ancient churches.

Most recently, two people were killed in a blast last week in a suspected showdown between two cocaine-smuggling groups believed to have links to South America's drug clans. At least five people died in similar incidents last year.

Balkans is a well-known transit zone for the smuggling of drugs toward Western Europe. Organized crime flourished in the area after the 1990s war.